Fil

Live coding in your browser with your favourite language.

http://fatiherikli.github.io/fil/

Features

• Currently supports Python, Ruby, Javascript, and Brainfuck.
• Runs on web workers.
• Uses localStorage API for your changes.

Implementation

• Uses Skulpt for Python interpreter.
• Uses Opal for Ruby interpreter.
• Built with React and Redux.

Todo

• Languages
  • LiveScript
  • SibilantJS or LispyScript
  • Elm-lang
  • Any language you want
• Build electron package.

Development

Clone the repository and run the following commands.

$ npm install
$ bower install
$ gulp build

After the installation, you can open index.html in your browser. Also you can run gulp watch command to listen and compile your changes.

Adding a new interpreter

Fil speaks with web workers to interpret the source codes. The workers listen message event for source code, and stream with stringified JSON object for the output of program.

The message should be a plain text, like this:

puts "hey".upcase

After the receiving, the worker will stream stringified json objects with type and data keys.

JSON.stringify({
    type: "stdout",
    data: "HEY"
})

The key of the object may be:

key	description
stdout	To print to the console
stderr	To show warning message
exit	To finish program

Lets create our worker.

// workers/markdown.js 
let sendMessage = (name, message) => {
  self.postMessage(JSON.stringify({
    type: name,
    data: message
  }));
}

let run = source => {
  var parser = new Markdown(),
      output;
  try {
    output = parser.parse(source)
    sendMessage('stdout', output);
  } catch (e) {
    sendMessage('stderr', {
      exception: 'ParseError',
      description: String(e)
    });
  }
  sendMessage('exit');
}

self.addEventListener('message', (e) => run(e.data));

After then, we should define this worker in /interpreters.yaml.

...
markdown:
  description: "Markdown"
  extension: "md"
  workerPath: "build/markdown.worker.js"
  editorMode: "markdown"
  includes:
  	- '{bowerPath}markdown-parser/src/markdow.min.js'

The configuration object may contains the following values:

key	description
description	Name of your interpreter that will shown on the console.
extension	File extensions will associated with the interpreter.
workerPath	Worker file. This file will be generated with gulp buildWorkers command.
editorMode	The mode of ACE Editor.
includes	The scripts will be concatenated with your worker.
parsingErrors	To keep apart the syntax errors and internal errors of interpreter.

Now we can build our new interpreter.

$ gulp buildWorkers

Using gulpfile ~/projects/fil/gulpfile.js
Starting 'buildWorkers'...
Finished 'buildWorkers' after 29 ms

That's it.